the glassing process. have become larger and thinner, their base strength has not changed, rather, t h e i r format means that i t i s now easier t o induce greater stresses during handling. The higher breakage rates have already led to increased losses f o r both manufacturer and integrator which must lead to higher cost for such products.In f a c t , as coverglasses ABSTRACT As a result of the gradual advances in solar cell technology and the demand for lighter, more efficient solar arrays, i t i s necessary t o Droduce solar cell coveralasses which are larger and thinner than tho;e previously available. reduction i n strength which can be the cause of breakages during manufacture and integration. Associated w i t h t h i s i s the present method of visual inspection of coverglasses for cosmetic defects which does not necessarily ensure that tgey will be strong enough to survive glassing processes. Techniques have therefore been developed to produce high strength coverglasses where mean strength improvement factors of 12 have been obtained; and also apparatus manufactured t o provide a repeatable proof strength t e s t f o r standard and h i g h strength coverglassesThis means t h a t there i s an apparent INTRODUCTION